JP2014051237A - Vehicular drive state control device and drive state control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular drive state control device and drive state control method which allow a vehicular drive state to be satisfactorily switched from a two-wheel drive state into a four-wheel drive state even during turning of a vehicle.SOLUTION: A first differential mechanism D/Ff, a first clutch device M, a second differential mechanism D/Fr, a second clutch device C/T, right/left-wheel number-of-revolutions sensors Vfr, Vfl, Vrr, and Vrl, an output shaft number-of-revolutions sensor Vt, a steering angle sensor Aw, an output shaft number-of-revolutions sensor Vp, a two-wheel rolling determination part 25, a steering angle determination part 26, a deceleration determination part 27, and a multi-disc clutch C/T are interconnected. A switching control device 28 is provided which performs control to bring a dog clutch M into an engaged state after disengaging the multi-disc clutch C/T at the timing corresponding to the detected differential number of revolutions or the calculated differential number of revolutions and thereafter performs control to engage the multi-disc clutch C/T.

Description

  The present invention relates to a vehicle drive state control device and a drive state control method capable of switching between a two-wheel drive state and a four-wheel drive state.

  Conventionally, as disclosed in Patent Document 1, there is a drive state control device that switches between a two-wheel drive state (rear wheel drive) and a four-wheel drive state in accordance with the traveling state of the vehicle. In the prior art disclosed in Patent Document 1, switching from the two-wheel drive state to the four-wheel drive state is realized by controlling connection of both the multi-plate clutch mechanism and the switching mechanism (dog clutch). The multi-plate clutch mechanism is provided between a first output shaft connected to the automatic transmission and a front wheel side differential provided between left and right driven wheels (front wheels) in a two-wheel drive state. The switching mechanism is provided between one axle of the left and right driven wheels (front wheels) and the front wheel side differential. In the prior art, since the switching mechanism is a dog clutch that does not have a synchronization device, the rotational speed of the driving wheel (rear wheel) and the driven wheel (front wheel) of the driven wheel (front wheel) are the same as when the vehicle is traveling straight in the two-wheel drive state. The connection is possible only when the rotational speed substantially matches. Thus, when the vehicle is traveling straight in the two-wheel drive state, the front wheels and the rear wheels have the same rotation speed, so the switching mechanism can be connected simultaneously with the connection of the multi-plate clutch mechanism. Switching to the four-wheel drive state is achieved smoothly.

JP 2011-178185 A

  However, when the vehicle is turning, the turning radii of the front wheels that are the steering wheels and the rear wheels that are the non-steering wheels are different, so that the front wheel rotation speed> the rear wheel rotation speed. For this reason, even if it tries to switch from a two-wheel drive state to a four-wheel drive state during vehicle turning, the technology shown in the prior art cannot connect the switching mechanism well.

  The present invention has been made in view of such circumstances, and provides a vehicle drive state control device and a drive state control method that can satisfactorily switch from a two-wheel drive state to a four-wheel drive state even while the vehicle is turning. The purpose is to provide.

  In order to solve the above-mentioned problem, a vehicle drive state control device according to claim 1 is rotationally coupled to an output shaft of a transmission connected to a drive source to transmit rotational drive force to one of left and right front wheels and rear left and right wheels. A first differential mechanism that distributes the wheels, a first clutch device that removably connects and disconnects the output shaft of the transmission and the other of the front left and right wheels and the rear left and right wheels; the first clutch device; A second differential mechanism that is rotationally connected to the output output shaft of the first clutch device between the other left and right wheels and distributes rotational driving force to the other left and right wheels; and an output output of the first clutch device. A second clutch device detachably connecting and disconnecting the shaft and the other left and right wheels; a left and right wheel rotational speed sensor for detecting the rotational speed of the front and rear left and right wheels; and a rotational speed of the output shaft of the transmission. An output shaft rotational speed sensor, a steering angle sensor for detecting a steering angle of the steering, and an output output shaft rotational speed sensor for detecting the rotational speed of the output output shaft of the first clutch device, One of the first and second clutch devices is a multi-plate clutch that is frictionally engaged by the engagement of the friction member and can connect the input shaft and the output shaft of the clutch device, and the other clutch device. Is a dog clutch capable of connecting the input shaft and the output shaft by fitting of a fitting portion when the differential rotational speed of the input shaft and the output shaft of the clutch device is equal to or lower than a predetermined rotational speed, A two-wheel drive determination unit that determines that the rotational driving force is input to only the left and right wheels and is in a two-wheel drive driving state, and the steering angle is operated more than a predetermined amount When switching to a steering angle determination unit to determine, a deceleration determination unit to determine that the vehicle is decelerating, and four-wheel drive, the multi-plate clutch is connected and the front detected by the left and right wheel rotation speed sensors Detected differential rotational speed between left and right wheels and rear left and right wheels, or computed differential rotational speed between the front left and right wheels and rear left and right wheels calculated from the rotational speed of the output shaft and the steering angle of the transmission A switching control unit that controls the dog clutch to be in a connected state after releasing the connection of the multi-plate clutch at a timing according to the control, and then controls the connection of the multi-plate clutch.

  According to a second aspect of the present invention, there is provided the vehicle drive state control device according to the first aspect, wherein a chamfer is formed at at least one tip portion of the fitting portion of the dog clutch.

  According to a third aspect of the present invention, in the vehicle drive state control device according to the first or second aspect, the one left and right wheel is the front left and right wheel.

  According to a fourth aspect of the present invention, there is provided a vehicle drive state control method comprising: a first difference that is rotationally coupled to an output shaft of a transmission connected to a drive source and distributes the rotational driving force to one of the left and right wheels of the front left and right wheels and the rear left and right wheels; And a first clutch device that detachably connects the output shaft of the transmission to the other of the front left and right wheels and the rear left and right wheels, and between the first clutch device and the other left and right wheels. A second differential mechanism that is rotationally coupled to the output output shaft of the first clutch device and distributes the rotational driving force to the other left and right wheels, and the output output shaft and the other left and right wheels of the first clutch device. A second clutch device that is detachably connected, a left and right wheel rotational speed sensor that detects the rotational speed of the front and rear left and right wheels, and an output shaft that detects the rotational speed of the output shaft of the transmission A rotation angle sensor; a steering angle sensor that detects a steering angle of the steering; and an output output shaft rotation speed sensor that detects a rotation speed of the output output shaft of the first clutch device. One of the second clutch devices is a multi-plate clutch that is frictionally engaged by the engagement of the friction member and can connect the input shaft and the output shaft of the clutch device, and the other clutch device is A dog clutch capable of connecting the input shaft and the output shaft by fitting a fitting portion when a differential rotational speed between an input shaft and an output shaft of the clutch device is equal to or less than a predetermined rotational speed, and only the one left and right wheels A two-wheel drive traveling determination step for determining that the rotational driving force is input to a two-wheel drive traveling state, and a steering angle determination step for determining that the steering angle is operated by a predetermined amount or more. And a deceleration determination step for determining that the vehicle is decelerating, and when switching to four-wheel drive, the front left and right wheels and the rear left and right wheels detected by the left and right wheel rotation speed sensors when the multi-plate clutch is connected. Or at a timing according to the calculated differential rotational speed between the front left and right wheels and the rear left and right wheels calculated from the rotational speed of the output shaft of the transmission and the steering angle. A switching control step of controlling the dog clutch to a connected state after releasing the connection of the multi-plate clutch and then controlling the connection of the multi-plate clutch.

  According to the invention which concerns on Claim 1, it is confirmed whether the vehicle is drive | working in a two-wheel drive state. After that, when the vehicle turns at a predetermined steering angle and is decelerating, first, a multi-plate clutch that is one clutch device is engaged. As a result, one or the other left and right wheels and the output output shaft are rotationally connected, and the one or the other left and right wheels and the rotation speed of the output output shaft simultaneously decrease as the vehicle decelerates. Then, after releasing the connection of the multi-plate clutch at a predetermined timing according to the differential rotational speed between the front left and right wheels and the rear left and right wheels, the dog clutch which is the other clutch device is connected. As described above, when the dog clutch is connected, the multi-plate clutch is in the disconnected state. For this reason, when the dog clutch is connected, no rotational drive force is input to the output output shaft and it is rotated only by inertial force, so there is a slight differential rotational speed between the front left and right wheels and the rear left and right wheels. Even if it is a dog clutch, it can be connected well without being restricted. Thereafter, the transition to the four-wheel drive state is achieved by connecting the multi-plate clutch. This makes it possible to satisfactorily switch from the two-wheel drive state to the four-wheel drive state even while the vehicle is turning.

  According to the second aspect of the present invention, in the dog clutch (the other clutch device), a chamfer having a tapered shape is formed at at least one tip of the fitting portion to be fitted. As a result, even when the dog clutch is connected, even if there is a large differential rotational speed between the input shaft and the output shaft of the dog clutch, the chamfer can be connected well, and the connection can be made in a short time, which is efficient.

  According to the invention of claim 3, one of the left and right wheels is a front left and right wheel. That is, the vehicle is front-wheel drive in the two-wheel drive state. In such a vehicle, when only the front left and right wheels are driven and the vehicle is turned, the switching mechanism is connected in advance to prepare for switching to the four-wheel drive state, so even when the front wheels slip Since switching to the four-wheel drive state can be performed satisfactorily and the slip state can be effectively dealt with, traveling performance and safety can be ensured.

  According to the invention of claim 4, each part (function) of the drive state control device of claim 1 can be replaced with a method executed by software. That is, the present invention can be realized as a method, and the effect is the same as that of the first aspect.

It is explanatory drawing which showed typically the power transmission system of the drive state control apparatus of the vehicle which concerns on the 1st Embodiment of this invention. (A) It is the figure which showed the chamfer shape of the spline in a sleeve, and a ring gear output-shaft outer spline. (B) It is the figure which showed another shape of the chamfer. It is a rotation speed-vehicle speed graph explaining the effect | action of 1st and 2nd embodiment which concerns on this invention. It is the flowchart 1 which concerns on this embodiment. It is the flowchart 2 which concerns on this embodiment. It is explanatory drawing which showed typically the power transmission system of the drive state control apparatus of the vehicle which concerns on the modification 1 of 1st Embodiment. It is a rotation speed-vehicle speed graph explaining the effect | action of the modification 1 and the modification 2 of this invention. It is explanatory drawing which showed typically the power transmission system of the drive state control apparatus of the vehicle which concerns on 2nd Embodiment. It is explanatory drawing which showed typically the power transmission system of the drive state control apparatus of the vehicle which concerns on the modification 2 of 2nd Embodiment. It is a rotation speed-vehicle speed graph explaining the effect | action of another embodiment of this invention.

  Hereinafter, a vehicle drive state control device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a power transmission system of a vehicle equipped with a drive state control device according to a first embodiment of the present invention. This drive state control device includes a front wheel (front wheel) side differential D / Ff (corresponding to the first differential mechanism of the present invention) and a rear wheel (rear wheel) side differential D / Fr (second differential of the present invention). Corresponding to the mechanism), a switching mechanism M (corresponding to the first clutch device and the other clutch device of the present invention and a dog clutch), and a multi-plate clutch mechanism C / T (second clutch device of the present invention and one of the other clutch devices). And a multi-plate clutch).

  Further, this drive state control device includes left and right wheel rotational speed sensors Vfr, Vfl, Vrr, Vrl, a transmission output shaft rotational speed sensor Vt, a steering angle sensor Aw, and a propeller shaft rotational speed sensor Vp (of the present invention). Corresponding to an output output shaft rotational speed sensor of the first clutch device), a switching mechanism M, a multi-plate clutch mechanism C / T, and an electronic control unit ECU for controlling the entire vehicle. Hereinafter, the front left and right wheels and the rear left and right wheels according to the present invention may be referred to only as front wheels and rear wheels. The front left and right wheels may be referred to as a left front wheel and a right front wheel, respectively, and the rear left and right wheels may be referred to as a left rear wheel and a right rear wheel, respectively.

  In the present embodiment, the vehicle is in a four-wheel drive state by controlling the switching mechanism M and the multi-plate clutch mechanism C / T to the connected state under the control of the electronic control unit ECU. Further, the vehicle is brought into the two-wheel drive state by controlling the switching mechanism M and the multi-plate clutch mechanism C / T to the disconnected state. In this embodiment, the front wheels are driven in the two-wheel drive state.

  As shown in FIG. 1, the vehicle has an engine E / G (corresponding to the drive source of the present invention) mounted in front of the front left and right wheels so that the output shaft is parallel to the front left and right wheels. ing. The spur gear connected to the output shaft 11 (output shaft) of the automatic transmission T / M is connected to the output shaft (not shown) of the automatic transmission T / M to the output shaft (not shown) of the engine E / G. The ring gear Rgf of the front wheel side differential D / Ff (first differential mechanism) is meshed and rotationally connected. The left and right output shafts of the front wheel side differential D / Ff are respectively connected to the left front wheel axle Afl and the right front wheel axle Afr.

  The automatic transmission T / M may be of any type, but in this embodiment, is an AT (automatic transmission) having a torque converter. However, the present invention is not limited to this, and an AMT (automated manual transmission) based on a manual transmission and an automated transmission mechanism and other automatic transmissions may be used.

  The front wheel side differential D / Ff has one of well-known configurations, and the torque of the output shaft 11 of the automatic transmission T / M is transmitted to the front left and right wheels via the right front wheel axle Afr and the left front wheel axle Afl. (Corresponding to one of the left and right wheels of the present invention). The rotational speed of the axles Afl, Afr (the rotational speed of the front left and right wheels) is “the rotational speed of the output shaft 11 of the automatic transmission T / M = the differential gear ratio × (the rotational speed of the axle Afl + the rotational speed of the axle Afr) / 2 ”.

  The ring gear Rgf of the front wheel side differential D / Ff is connected to the output shaft 12 disposed on the outer periphery of the axle Afr of the right front wheel and rotates integrally with the output shaft 12. The output shaft 12 is rotationally connected to an input shaft 31 (corresponding to the input shaft of the switching mechanism M (the other clutch device) of the present invention) of the switching mechanism M (first clutch device). The input shaft 31 is rotatably supported on the axle Afr via a bearing (not shown). The output shaft 12 (input shaft 31) is rotationally coupled to the propeller shaft Sp (the output output shaft of the other clutch device) via the switching mechanism M (first clutch device) and the hypoid gear 14.

  Specifically, the output shaft 32 (corresponding to the output shaft of the switching mechanism M (the other clutch device) of the present invention) of the switching mechanism M (first clutch device) is rotationally connected to the input shaft 15 of the hypoid gear 14. The The output shaft of the hypoid gear 14 whose output direction is changed by 90 degrees with respect to the input shaft 15 is rotationally connected to the propeller shaft Sp. The propeller shaft Sp is rotationally coupled via the rear left and right wheels (the other left and right wheels) and the rear wheel side differential D / Fr (second differential mechanism). Thereby, the switching mechanism M connects and disconnects the output shaft 11 and the rear left and right wheels of the automatic transmission T / M.

  Note that the switching mechanism M in this embodiment is a dog clutch, and the rotational speed (rotational speed) between the output shaft 11 and the propeller shaft Sp during connection control of the output shaft 11 and the propeller shaft Sp of the automatic transmission T / M. Is not equipped with a rotation synchronizer (synchronizer). Therefore, in order to control the switching mechanism M from the disconnected state to the connected state, the rotational speeds of the output shaft 11 and the propeller shaft Sp of the automatic transmission T / M, that is, the switching mechanism M (first clutch device). The input shaft 31 and the output shaft 32 need to be equal to or less than a predetermined differential rotation speed. Note that the predetermined differential rotational speed is different for each switching mechanism M, and is derived by prior examination. However, a rotation synchronizer (synchronizer) may be provided. In this case, when the input shaft 31 and the output shaft 32 are equal to or less than a predetermined differential rotational speed, the capacity of the rotation synchronizer (synchronizer) may be small, thereby making the input shaft 31 and the output shaft 32 smoother. Connection is possible.

  As shown in FIG. 1, for example, the switching mechanism M includes an input shaft outer spline 16 (corresponding to a fitting portion in the present invention) formed on the outer periphery of the input shaft 31 and an outer periphery of the output shaft 32 of the switching mechanism M. Output shaft spline 17 (corresponding to the fitting portion in the present invention) formed on the input shaft, and the input shaft outer spline 16 and the output shaft spline 17 fitting portion and the inner spline 19 (corresponding to the fitting portion in the present invention). And a fork 21 that adjusts the position by moving the sleeve 18 in the axial direction of the output shaft 12.

  An inner spline 19 is formed on the inner peripheral surface of the sleeve 18 formed in a cylindrical shape so as to be able to mesh with the input shaft outer spline 16 and the output shaft outer spline 17. In the cut state of the switching mechanism M, the inner spline 19 of the sleeve 18 meshes with only one of the input shaft outer spline 16 and the output shaft outer spline 17.

  When the electronic control unit ECU determines to change the switching mechanism M from the disconnected state to the connected state in order to switch the vehicle to the four-wheel drive state, the electronic control unit ECU is engaged with the sleeve 18 by the operation of the actuator (not shown). The fork 21 to be moved is moved to the output shaft 12 side. As a result, the inner spline 19 of the sleeve 18 already engaged with the output shaft outer spline 17 is engaged (fitted) with the input shaft outer spline 16. Then, the output shaft 12 of the ring gear Rgf and the input shaft 15 of the hypoid gear are rotationally connected via a sleeve 18, whereby the output shaft 11 and the propeller shaft Sp of the automatic transmission T / M are rotationally connected ( (See the state in FIG. 1).

  At this time, the actuator that operates the switching mechanism M may be of any type. For example, the rotation of the motor may be converted into a linear motion, and the sleeve 18 may be operated by the linear motion. Alternatively, after the rotation of the motor is converted into a linear motion, a predetermined hydraulic pressure is generated by the linear motion, and the fork 21 may be operated by the hydraulic pressure.

  At this time, the differential rotation speed Rfr between the input shaft 31 and the output shaft 32 of the switching mechanism M needs to be equal to or less than a predetermined differential rotation speed Rm. Therefore, when the detection data R1 of the output shaft rotational speed sensor Vt and the detection data R2 of the propeller shaft rotational speed sensor Vp are constantly monitored, and the calculated differential rotational speed (R1-R2) becomes equal to or less than a predetermined value Rm. The movement control of the sleeve 18 is executed and the switching mechanism M is connected.

  FIG. 2A is a development view of the input shaft off-line spline 16 and the sleeve inner spline 19. Both the input shaft outer spline 16 and the sleeve inner spline 19 are developed so that the fitting portion can be seen. As shown in FIG. 2A, a chamfer 19b is formed at the end of the convex portion 19a of the spline 19 in the sleeve on the input shaft off-spline 16 side. A chamfer 16b is also formed at the end of the convex portion 16a of the input shaft off-spline 16 on the side of the in-sleeve spline 19 side. The chamfers 19b and 16b here refer to the tips of the convex portions 16a and 19a formed at an acute angle.

  By providing the chamfers 16b and 19b, the tip of the chamfer 19b of the convex portion 19a of the in-sleeve spline 19 is easily engaged with the concave portion 16c of the off-axis spline 16 to enter. Further, the front end of the chamfer 16b of the convex portion 16a of the input shaft outer spline 16 is easily engaged with the concave portion 19c of the in-sleeve spline 19 to enter. Thus, even if there is a predetermined differential rotational speed between the input shaft 31 and the sleeve 18 (that is, the output shaft 32), the differential rotational speed is allowed and the input shaft 31 and the output shaft 32 are connected for a short time. It is efficient because it can be rotated and connected with.

  The chamfer may be provided only on one of the convex portion 16 a of the input shaft off-line spline 16 and the convex portion 19 a of the in-sleeve spline 19. Further, the sleeve 18 is always meshed with the input shaft outside spline 16, and is moved toward the output shaft outside spline 17 under the control of the electronic control unit ECU, so that the sleeve inside spline 19 and the output shaft outside spline 17 are meshed. In this case, the chamfer may be provided on at least one of the end on the output shaft 32 side of the convex portion 19 a of the spline 19 in the sleeve and the end on the sleeve 18 side of the convex portion 17 a of the spline 17 outside the output shaft. Further, the shape of the chamfer is not limited to that shown in FIG. 2A, but may be a shape having an inclination in only one direction as shown in FIG. 2B (see 16d and 19d). The effect can be expected sufficiently.

  The rear wheel side differential D / Fr (second differential mechanism) connected to the propeller shaft Sp has one of well-known configurations, and the torque of the propeller shaft Ap is set to the right rear wheel axle Arr and the left rear wheel. It is distributed to the left and right rear wheels via the wheel axle Arl. The propeller shaft Sp meshes with the ring gear Rgr of the rear wheel side differential D / Fr and is rotationally connected. The two output shafts of the rear wheel side differential D / Fr are connected to the right rear wheel axle Arr and the left rear wheel axle Arl. Each is connected. The rotational speeds of the axles Arl and Arr (the rotational speeds of the left and right rear wheels) have a relationship of “the rotational speed of the propeller shaft Sp = the differential gear ratio × (the rotational speed of the axle Arl + the rotational speed of the axle Arr) / 2”.

  A multi-plate clutch mechanism C / T (corresponding to the second clutch device and corresponding to one clutch device) is interposed on the axle Arr of the right rear wheel. The multi-plate clutch mechanism C / T has one of known configurations. In the multi-plate clutch mechanism C / T, an actuator (not shown) is controlled by the electronic control unit ECU. As a result, it is possible to switch between a disconnected state where the torque of the propeller shaft Ap is not distributed to the right rear wheel (axle Arr) and an engaged state where the torque of the propeller shaft Ap is distributed to the right rear wheel (axle Arr). ing.

  As shown in FIG. 1, the multi-plate clutch mechanism C / T has a plurality of friction members 22 and friction members 23. The friction member 22 has an annular shape, and the outer peripheral portion thereof is spline-engaged with the inner peripheral surface of the cylindrical portion of the cylindrical case 24. On the side surface of the case 24 on the side of the axle Arr (corresponding to the output shaft of the multi-plate clutch mechanism C / T according to the present invention), the center of the side surface is spline-engaged with the axle Arr and is movable in the axial direction with respect to the axle Arr. It has become.

  The friction member 23 has a disk shape, and the center of the disk is spline-engaged with the output shaft of the rear wheel differential D / Fr (corresponding to the input shaft of the multi-plate clutch mechanism C / T according to the present invention). ing. The friction members 22 and the friction members 23 are alternately arranged in the axial direction of the axle Arr. When the actuator (not shown) is operated by the electronic control unit ECU and the case 24 is moved in the direction of the rear wheel side differential D / Fr, the friction member 22 is frictionally engaged with the friction member 23 and the rear wheel side differential D / Fr is moved. The output shaft (input shaft of the multi-plate clutch mechanism C / T) and the axle Arr (output shaft of the multi-plate clutch mechanism C / T) are rotationally connected.

  Specifically, the multi-plate clutch mechanism C / T adjusts the friction engagement amount between the friction member 22 and the friction member 23 according to the operation amount of an actuator (not shown), and the maximum torque that can be distributed to the axle Arr (hereinafter, “ (Referred to as "multi-plate clutch transmission torque"). When the multi-plate clutch transmission torque is “0”, it corresponds to the “disengaged state”, and when the multi-plate clutch transmission torque is larger than “0”, it corresponds to the “engaged state”. A state where the multi-plate clutch mechanism C / T is completely engaged and the multi-plate clutch transmission torque is maximum is referred to as a connected state.

  As described above, when the multi-plate clutch mechanism C / T and the switching mechanism M are both in the “disengaged state”, this drive state control device is in the two-wheel drive state (in the present embodiment, the front wheel drive state). When the plate clutch mechanism C / T is “between the engaged state and the connected state” and the switching mechanism M is in the “connected state”, the four-wheel drive state is set. Hereinafter, the two-wheel drive may be referred to as “2WD” and the four-wheel drive may be referred to as “4WD”.

  The left and right wheel rotation speed sensors Vfr, Vfl, Vrr, Vrl respectively detect the rotation speed (= rotational speed) of the corresponding wheel. The propeller shaft rotational speed sensor Vp detects the rotational speed (= rotational speed) of the propeller shaft Ap. The output shaft rotational speed sensor Vt detects the rotational speed (= rotational speed) of the output shaft 11 of the automatic transmission T / M. The steering angle sensor Aw detects the steering angle θ of the steering wheel St operated by the driver.

  The electronic control unit ECU is a microcomputer having one of known configurations. The electronic control unit ECU is connected to the left and right wheel rotational speed sensors Vfr, Vfl, Vrr, Vrl, the propeller shaft rotational speed sensor Vp, the output shaft rotational speed sensor Vt, and the steering angle sensor Aw, respectively, and acquires data. Further, the electronic control unit ECU is connected to each actuator for operating the multi-plate clutch mechanism C / T and the switching mechanism M (the actuator and the connection line are not shown).

  The electronic control unit ECU processes information acquired from each sensor and controls the states of the engine E / G and the automatic transmission T / M according to the state of the vehicle derived from the processed results. Further, the electronic control unit ECU operates an actuator (not shown) to control the state (multi-plate clutch transmission torque) of the multi-plate clutch mechanism C / T according to the rotational speed of the four wheels, etc. An actuator (not shown) for controlling the state of the mechanism M (“connected state” or “disconnected state”) is controlled.

  Specifically, it is assumed that, for example, one of the front left and right wheels slips during traveling with 2WD (front wheel drive). At this time, in the front left and right wheels, the torque from the output shaft 11 is transmitted to the slipped wheel by the action of the front wheel side differential D / Ff, and the wheel rotates idly, and the torque is not transmitted to the grounded wheel. . Therefore, when the electronic control unit ECU detects a slip on any of the left and right wheels among the front left and right wheels, the electronic control unit ECU performs control to switch from the 2nd drive to the 4th drive. As a result, torque is transmitted to the rear left and right wheels, and smooth running is obtained.

  A method of switching from 2WD to 4WD will be described. For example, during straight running with 2WD (front wheel drive), both the switching mechanism M and the multi-plate clutch mechanism C / T are in a disconnected state. For this reason, no torque is transmitted to the propeller shaft Sp, and the propeller shaft Sp is in a stopped state. At this time, since the vehicle is traveling straight, the front left and right wheels and the rear left and right wheels have the same rotational speed. Therefore, in order to switch to the 4WD, the electronic control unit ECU first gradually engages the multi-plate clutch mechanism C / T from the disconnected state to the connected state. As a result, the propeller shaft rotational speed R2 of the propeller shaft Sp is eventually increased to the rotational speed of the rear left and right wheels and becomes the same. That is, since the rotation speed of the propeller shaft Sp is the same as the rotation speed of the front left and right wheels rotating at the same rotation speed as that of the rear left and right wheels, the switching mechanism M is configured by a dog clutch without a synchronization mechanism. However, connection control is performed well in a short time.

  However, for example, when the driver turns the vehicle by operating the steering St during traveling with 2WD (front wheel drive), the situation is different from the above. In other words, during turning of the vehicle, a predetermined differential rotation occurs between the front left and right wheels and the rear left and right wheels due to the difference in average turning radius between the front left and right wheels and the rear left and right wheels, and the front left and right wheel rotation speed> Rear left and right wheel rotation speed.

  For this reason, for example, when one of the front left and right wheels slips during the turning of the vehicle, the rotation of the propeller shaft Sp that is rotationally connected to the rear left and right wheels even if switching to the four-wheel drive is performed as described above. There is a differential rotation between the number and the number of rotations of the front left and right wheels (average value). As a result, it becomes difficult to connect the switching mechanism M constituted by the dog clutch without the synchronization mechanism.

  In such a case, according to the present invention, the switching mechanism M is connected in advance during turning of the vehicle to prepare for switching from the 2nd to the 4th. When one of the front left and right wheels slips during turning of the vehicle, the multi-plate clutch mechanism C / T is controlled to be switched from the 2nd to the 4th. The electronic control unit ECU that constitutes a part of the drive state control unit in the present invention includes a two-wheel drive traveling determination unit 25, a steering angle determination unit 26, a deceleration determination unit 27, and a switching control unit 28. .

  The two-wheel drive traveling determination unit 25 determines that the vehicle is traveling in a two-wheel drive state when a rotational driving force is input to only the front left and right wheels (one left and right wheel). At this time, when the rotational driving force is input to only the front left and right wheels (one of the left and right wheels) and the vehicle is traveling (front wheel driving state), the multi-plate clutch mechanism C / T and the switching mechanism M are in the disconnected state. Therefore, the rotation of the propeller shaft Sp is stopped. Therefore, it may be simultaneously confirmed that the rotation of the propeller shaft Sp (the output output shaft of the first clutch device) is stopped. Thereby, reliability can be improved with respect to the determination of the 2WD running state. The rotation of the propeller shaft Sp is detected by the propeller shaft rotation speed sensor Vp.

  In the present invention, the detection of data by the left and right wheel rotation speed sensors Vfr, Vfl, Vrr, Vrl, the propeller shaft rotation speed sensor Vp, the output shaft rotation speed sensor Vt, and the steering angle sensor Aw is always executed, and the detected data is It is assumed that it is stored in a storage unit (not shown).

  The steering angle determination unit 26 acquires the steering angle θ data detected by the steering angle sensor Aw, and determines whether or not the steering angle θ is operated by a predetermined amount θm or more. At this time, the steering angle θ equal to or greater than the predetermined amount θm means that, by turning the vehicle, the differential rotational speed between the rear left and right wheels (average rotational speed) and the front left and right wheels (average rotational speed) exceeds the predetermined amount Rm. This is to determine whether the turning radius of the vehicle is such that it is difficult to connect M in a short time, and may be set arbitrarily based on prior experiments or the like.

  The deceleration determination unit 27 determines that the vehicle is decelerating. In the present invention, as shown in the graph of FIG. 3, when the vehicle is decelerating, the rotational speeds of the front left and right wheels (average value) and the rear left and right wheels (average value) having differential rotation gradually approach each other. This is used to connect the switching mechanism M. Therefore, it is determined whether or not the requirement for deceleration is satisfied. Also at this time, the deceleration threshold value indicating the degree of deceleration used for the determination can be arbitrarily set so that the time until the switching mechanism M is connected is a desired time. However, the deceleration determination may be performed in any way.

  Since the switching control unit 28 switches to the four-wheel drive state, the front left and right wheels detected by the left and right wheel rotation speed sensors Vfr, Vfl, Vrr, and Vrl after the multi-plate clutch mechanism C / T is completely connected. The multi-plate clutch mechanism C / T is disengaged (disconnected) at a timing corresponding to the detected differential rotation speed between the average value of the rear wheel and the average value of the rear left and right wheels, and the other clutch device (first clutch device) is used. A certain switching mechanism M is controlled to be connected. At this time, the timing according to the detected differential rotational speed is, for example, immediately after releasing the connection of the multi-plate clutch mechanism C / T, and can be connected by the switching mechanism M which is the other clutch device (first clutch device). The timing at which the differential rotation speed becomes. Thereafter, the multi-plate clutch mechanism C / T is connected and controlled to be in a four-wheel drive state.

  Next, the operation of the drive state control device will be described with reference to the flowcharts 1 and 2 in FIGS. This routine is stored in the ROM in the electronic control unit ECU, and is started and executed every elapse of a predetermined time (for example, 6 msec) by the CPU in the electronic control unit ECU. Initially, it is assumed that the vehicle is traveling in a two-wheel drive state (front wheel drive).

  In the flowchart 1, the detection of the data by the left and right wheel rotational speed sensors Vfr, Vfl, Vrr, Vrl, the output shaft rotational speed sensor Vt, the propeller shaft rotational speed sensor Vp, and the steering angle sensor Aw is always performed in steps S11 to S14. Storage in an abbreviated storage unit is executed.

  In the flowchart 2, in step S21 (steady driving determination step), the two-wheel drive determination unit 25 causes the electronic control unit ECU to control the multi-plate clutch mechanism C / T and the switching mechanism M to be in a disconnected state, and the vehicle is driven by two wheels. It is determined whether or not the vehicle is being controlled to travel at If it is determined that control is being performed by the second drive, the process moves to step S22, and propeller shaft rotation speed R2 data is acquired. If it is determined that the two-wheel drive control is not being performed, the program ends and the process returns to the start.

  In step S23, it is determined whether or not the propeller shaft speed R2 is zero. If it is determined that the rotational speed is 0, the process proceeds to step S24. If it is determined that the rotational speed is not 0, the program is terminated and the process returns to the start. This step is a step for determining whether or not the control by the two-wheel drive is being performed based on the propeller shaft rotation speed R2 and improving the reliability of the determination. Note that step S22 and step S23 may be omitted.

  In step S24, the output shaft rotation speed R1 and the steering angle θ are acquired from the storage unit. In step S25 (deceleration determination step), the deceleration determination unit 27 determines whether or not the vehicle is decelerating from the acquired output shaft rotation speed R1. At this time, whether or not the vehicle is decelerating may be determined based on, for example, whether or not a predetermined deceleration set in advance has been reached. If it is determined that the vehicle is decelerating, the process proceeds to step S26. If it is determined that the vehicle is not decelerating, the program is terminated and the process returns to the start.

  In step S26 (steering angle determination step), it is determined from the acquired steering angle θ whether the operated steering angle is equal to or greater than a predetermined amount θm. If it is determined that the predetermined amount θm is greater than or equal to the predetermined amount θm, the process proceeds to step S27.

  In step S27, the electronic control unit ECU controls the multi-plate clutch mechanism C / T, which is one clutch device and the second clutch device, to the connected state. At this time, since the rear left and right wheels are rotating and the propeller shaft Ap is stopped, the multi-plate clutch mechanism C / T gradually moves from the disconnected state to the connected state as shown in part A of the graph of FIG. And finally connected. As a result, the rotational speed R2 of the propeller shaft Ap becomes equal to the rotational speed of the rear left and right wheels.

  In step S28 (switching control step), the rotational speeds of the rear left and right wheels and the front left and right wheels are acquired. In step S29 (switching control step), the difference rotational speed Rfr between the rotational speed of the rear left and right wheels (average rotational speed) and the rotational speed of the front left and right wheels (average rotational speed) that is equal to the propeller shaft rotational speed R2 is set. Calculate.

  In step S30 (switching control step), it is determined whether or not the timing at which the differential rotational speed Rfr of the front, rear, left and right wheels is equal to or less than a predetermined amount Rm is determined. At this time, in the present embodiment, the timing at which the predetermined rotational speed Rm is reached means that the propeller shaft Sp that has become free when the multi-plate clutch mechanism C / T is disconnected (released) and the driving force is This is the timing at which the rotational speed becomes a difference that allows the switching mechanism M to connect to the front left and right wheels that are input and in a driving state. And if it becomes predetermined differential rotation speed Rm, it will move to step S31. If the predetermined differential rotational speed Rm has not been reached, steps S28 to S30 are repeatedly executed until the predetermined differential rotational speed Rm is reached.

  In step S31 (switching control step), the connection of the multi-plate clutch mechanism C / T is released and a disconnected state is established. In step S32, the switching mechanism M, which is the other clutch device (first clutch device), is controlled to be in a connected state, and the program ends. As described above, in the present embodiment, the switching mechanism M is controlled to the connected state immediately after the connection of the multi-plate clutch mechanism C / T is released.

  At this time, the end on the input shaft outside spline 16 side of the projection 19a of the in-sleeve spline 19 of the switching mechanism M (dog clutch) and the end of the projection 16a of the input shaft outside spline 16 on the side of the in-sleeve spline 19 Chamfers 19b and 16b are respectively formed. As a result, when the switching mechanism M is connected, the chamfers 19b and 16b are connected to the recesses 16c of the input shaft off-spline 16 and the sleeve even if there is a predetermined differential rotational speed Rfr between the front left and right wheels and the rear left and right wheels. Engage and engage with the recess 19c of the spline 19 in a short time. Thereby, the switching mechanism M can be connected in a short time, and the efficiency is high. With this control, preparation for switching to the 4WD is completed.

  Thereafter, in step S32 (switching control step), connection control of the multi-plate clutch mechanism C / T is performed again. As a result, even when the vehicle is turning, torque is transmitted to the rear left and right wheels, and traveling with four-wheel drive becomes possible.

  As is clear from the above description, in the vehicle drive state control device according to the present invention, first, it is confirmed whether or not the vehicle is in the two-wheel drive state where the vehicle is traveling in the two-wheel drive state. Thereafter, when the vehicle is decelerating and turning at a predetermined steering angle θm, the multi-plate clutch mechanism C / T (one clutch device (second clutch device)) is first brought into a connected state. As a result, the rear left and right wheels (the other left and right wheels) that are rotationally connected by the multi-plate clutch mechanism C / T and the propeller shaft Sp are eventually rotationally connected.

  The number of rotations of the rear left and right wheels (the other left and right wheels) and the propeller shaft Sp are reduced simultaneously with the deceleration of the vehicle. Then, after disconnecting the multi-plate clutch mechanism C / T at a predetermined timing according to the detected differential rotational speed Rfr between the front left and right wheels and the rear left and right wheels, the switching mechanism M (the other clutch device (the first clutch) Control the device)) to the connected state.

  Thus, when connecting the switching mechanism M, the multi-plate clutch mechanism C / T is in a disconnected state. For this reason, since no rotational driving force is input to the propeller shaft Sp and the propeller shaft Sp is rotated only by the inertial force, the propeller shaft Sp is restricted even if there is a predetermined differential rotational speed between the front left and right wheels and the rear left and right wheels. Therefore, the switching mechanism M can be connected well. Thereafter, the four-wheel drive state is achieved by connecting the multi-plate clutch mechanism C / T. This makes it possible to satisfactorily switch from the two-wheel drive state to the four-wheel drive state even while the vehicle is turning.

  Further, in the present embodiment, the chamfers 19b and 16b are provided at the end portions on the sleeve inner spline 19 side of the convex portion 19a of the in-sleeve spline 19 of the sleeve 18 and the convex portion 16a of the input shaft off-line spline 16 respectively. Is formed. As a result, even if there is a predetermined differential rotational speed Rfr between the front left and right wheels and the rear left and right wheels, the switching mechanism M meshes well and can be connected in a short time, which is efficient.

  Moreover, in this embodiment, one left-right wheel is a front left-right wheel. That is, the vehicle is front-wheel drive in the two-wheel drive state. In such a vehicle, when only the front left and right wheels are driven and steered, the switching mechanism M is connected in advance and preparation for switching to the four-wheel drive state is made. In addition, since it is possible to satisfactorily switch to the four-wheel drive state and to effectively cope with the slip state, it is possible to ensure traveling performance and safety.

  Next, Modification 1 of the vehicle drive state control device of the first embodiment will be described with reference to FIG. In the first modification of the first embodiment (hereinafter referred to as only the first modification), the arrangement positions of the multi-plate clutch mechanism C / T and the switching mechanism M are changed with respect to the first embodiment. Note that the vehicle drive control device of the first modification is different from the drive state control device of the first embodiment in that only part of the multi-plate clutch mechanism C / T and the switching mechanism M is changed. Therefore, only the changes will be described, and description of similar parts will be omitted. The same parts and the like will be described with the same reference numerals.

  In the first modification, the multi-plate clutch mechanism C / T is the first clutch device and one clutch device. The switching mechanism M is the second clutch device and the other clutch device. As shown in FIG. 6, the ring gear Rgf of the front wheel side differential D / Ff is connected to the output shaft 12 disposed on the outer periphery of the axle Afr of the right front wheel, and rotates integrally with the output shaft 12. The output shaft 12 is rotationally coupled to an input shaft 45 (corresponding to the input shaft of one clutch device of the present invention) connected to the case 44 of the multi-plate clutch mechanism C / T.

  The multi-plate clutch mechanism C / T has a plurality of friction members 42, a friction member 43, the case 44 and the output shaft 44a (corresponding to the output shaft of one clutch device of the present invention). The friction member 42 is spline-engaged with an inner peripheral surface of the cylindrical portion of the case 44 having an annular shape and an outer peripheral portion having a cylindrical shape.

  The output shaft 44a is supported on the axle shaft Afr so as to be free to rotate. The friction member 43 is spline-engaged with the outer peripheral surface of the output shaft 44a. The case 44 and the output shaft 44a are relatively movable in the axial direction. The output shaft 44 a is rotationally connected to the input shaft 15 of the hypoid gear 14. In this way, the output shaft 11 of the automatic transmission T / M and the propeller shaft Sp (the output output shaft of the first clutch device) are rotationally connected via the multi-plate clutch mechanism C / T and the hypoid gear 14. ing.

  As described above, the friction member 43 has a disk shape, and the center of the disk is spline-engaged with the outer periphery of the output shaft 44a of the multi-plate clutch mechanism C / T. The friction members 42 and the friction members 43 are alternately arranged in the axial direction of the input shaft 45. When the electronic control unit ECU operates an actuator (not shown) to move the case 44 in the front wheel side differential D / Ff direction, the friction member 42 is frictionally engaged with the friction member 43, and the multi-plate clutch mechanism C / The T input shaft 45 and the output shaft 44a are rotationally coupled. That is, the output shaft 11 and the propeller shaft Sp of the automatic transmission T / M are rotationally connected.

  The operation of the modified example 1 configured as described above is the same as in the flowcharts 1 and 2. However, there are differences in specific operation contents. That is, in step S27 of the flowchart 2, the multi-plate clutch mechanism C / T (which is the first clutch device and the one-side clutch device) is controlled to be in the connected state, whereby the propeller shaft Ap rotates the number of front left and right wheels. (See the graph in FIG. 7). This point is different, and in the first embodiment, the propeller shaft Ap has the same rotational speed as the rear left and right wheels.

  In step S28 to step S30, the switching control unit 28 determines the front left and right wheel rotation speed (average rotation speed) equal to the propeller shaft rotation speed R2 and the rear left and right wheel rotation speed (average rotation speed). It is determined whether or not the differential rotational speed Rfr of the front, rear, left and right wheels has reached a predetermined differential rotational speed Rm. And if it becomes predetermined differential rotation speed Rm, it will move to step S31. Steps S31 to S33 are the same as those in the flowchart 2.

  As described above, even when the switching mechanism M in the first modification is connected, the propeller shaft Sp is not input with the rotation force and is rotated only by the inertial force, as in the first embodiment. Therefore, even if there is a predetermined differential rotational speed Rm between the rotational speed of the front left and right wheels and the rotational speed of the rear left and right wheels, the switching mechanism M can be connected well without being restricted. This makes it possible to satisfactorily switch from the two-wheel drive state to the four-wheel drive state even while the vehicle is turning.

  Next, the drive state control apparatus in 2nd Embodiment is demonstrated based on FIG. The second embodiment is different from the first embodiment in the drive wheels at the time of two-wheel drive of the vehicle. In other words, the vehicle in the first embodiment is a front wheel drive in which the front left and right wheels are driven in the case of the second driving. However, the vehicle according to the second embodiment is a rear-wheel drive vehicle in which the rear left and right wheels are driven in the case of two-wheel drive. Hereinafter, only changes to the first embodiment will be described in detail, and description of similar parts will be omitted. The same parts and the like will be described with the same reference numerals.

  FIG. 8 shows a power transmission system of a vehicle equipped with the drive state control device according to the second embodiment. This drive state control device includes a rear wheel side differential D / Fr (corresponding to the first differential mechanism according to the present invention), a front wheel side differential D / Ff (corresponding to the second differential mechanism according to the present invention), Multi-plate clutch mechanism C / T (corresponding to the first clutch device and one clutch device according to the present invention and a multi-plate clutch) and switching mechanism M (second clutch device and the other clutch device according to the present invention) And a dog clutch).

  As shown in FIG. 8, the vehicle has an engine E / G (a drive source according to the present invention) mounted between the front left and right wheels (the other left and right wheels) so that the output shaft is orthogonal to the axles of the front left and right wheels. Applicable) The input shaft (not shown) of the automatic transmission T / M is connected to the output shaft (not shown) of the engine E / G, and the output shaft 41 (output shaft) of the automatic transmission T / M is connected to the rear wheel side differential D /. It is connected to Fr (first differential mechanism). The left and right output shafts of the rear wheel side differential D / Fr are connected to the left rear wheel (one left and right wheel) axle Arl and the right rear wheel (one left and right wheel) axle Arr, respectively.

  A multi-plate clutch mechanism C / T is interposed on the output shaft 41. The configuration of the multi-plate clutch mechanism C / T is the same as that described in the first embodiment, and a detailed description thereof will be omitted. In the multi-plate clutch mechanism C / T, the input shaft (corresponding to the input shaft of one clutch device of the present invention) is also used as the output shaft 41.

  The output shaft 58 of the multi-plate clutch mechanism C / T (corresponding to the output shaft of one clutch device of the present invention) is connected to the rotating shaft of the first sprocket 55. The first sprocket 55 is connected to the second sprocket 56 via a chain 57. The second sprocket 56 is fixed to one end of the propeller shaft Sp (corresponding to the output output shaft of the first clutch device). The other end of the propeller shaft Sp is connected to the front wheel side differential D / Ff. Thus, when the multi-plate clutch mechanism C / T is connected and controlled, the torque of the output shaft 41 (output shaft) is input to the front wheel side differential D / Ff via the multi-plate clutch mechanism C / T and the propeller shaft Sp. The

  The left and right output shafts of the front wheel side differential D / Ff (second differential mechanism) are the left front wheel axle Afl and the input shaft 61 of the switching mechanism M (second clutch device) (the input shaft of the other clutch device of the present invention). Correspond to each other). The output shaft 62 (corresponding to the output shaft of the other clutch device of the present invention) of the switching mechanism M (second clutch device) is connected to the axle Afr of the right front wheel. As described in the first embodiment, the switching mechanism M does not have a rotation synchronization device (synchronizer) in which the input shaft 61 and the output shaft 62 of the switching mechanism M are connected by the movement of the sleeve 59 in the axial direction. It is a dog clutch. However, you may have a rotation synchronizer (synchronizer). In this case, the rotational speed R2 of the propeller shaft Sp is raised to coincide with the rotational speed Rr of the rear left and right wheels by connection control of the multi-plate clutch mechanism C / T. Then, since the switching mechanism M is connected when the difference rotational speed Rfr between the propeller shaft Sp and the front left and right wheel rotational speeds Rf becomes a predetermined value or less, the capacity of the rotation synchronizer (synchronizer) is small. Good. Other effects provided with the rotation synchronizer (synchronizer) include reduction of connection shock and extension of the life of the connection portion of the switching mechanism M.

  The operation and action of the drive state control apparatus according to the second embodiment configured as described above are the same as those described in the first embodiment based on the flowcharts 1 and 2. Thereby, the effect similar to 1st Embodiment is acquired.

  Next, Modification 2 of the second embodiment will be described with reference to FIG. The second modification of the second embodiment (hereinafter referred to only as the second modification) replaces the arrangement positions of the multi-plate clutch mechanism C / T and the switching mechanism M with respect to the second embodiment. As described above, the vehicle drive control device according to the second modified example is different from the drive state control device according to the second embodiment in that a part of the multi-plate clutch mechanism C / T and the switching mechanism M is changed. Therefore, only the changes will be described, and description of similar parts will be omitted. The same parts and the like will be described with the same reference numerals.

  In the second modification, the multi-plate clutch mechanism C / T (multi-plate clutch) is a second clutch device and one clutch device. The switching mechanism M (dog clutch) is the first clutch device and the other clutch device. The input shaft 65 (corresponding to the input shaft of one clutch device of the present invention) of the multi-plate clutch mechanism C / T is always rotationally connected to the output shaft of the front wheel side differential D / Ff (second differential mechanism). Yes. The output shaft 66 (corresponding to the output shaft of one clutch device of the present invention) of the multi-plate clutch mechanism C / T is connected to the axle Afr of the right front wheel. By connecting the multi-plate clutch mechanism C / T from the disconnected state to the connected state via the engaged state, the connection / disconnection between the propeller shaft Sp and the front left and right wheels is controlled.

  The switching mechanism M is a dog clutch having a sleeve 69 provided between the propeller shaft Sp and the output shaft 41 via a spur gear 71 and a spur gear 72. The switching mechanism M has an input shaft (corresponding to the input shaft of the other clutch device of the present invention) and an output shaft 73 (corresponding to the output shaft of the other clutch device of the present invention). The input shaft of the switching mechanism M is also used as the output shaft 41. The output shaft 73 of the switching mechanism M is connected to the rotation shaft of a spur gear 72 provided so as to be free to rotate with respect to the output shaft 41. A spur gear 71 that always meshes with the spur gear 72 is fixed to the propeller shaft Sp.

  In the switching mechanism M, the sleeve 69 reciprocates in the axial direction of the output shaft 41, thereby disconnecting the connection between the output shaft 41 and the spur gear 72 and extending between the output shaft 41 and the propeller shaft Sp. Disconnect the connection. Although the detailed description of the configuration and mechanism of the switching mechanism M is omitted, it is the same as the switching mechanism M described above.

  The operation and action of the drive state control device according to the second modification configured as described above are the same as those described in the first modification of the first embodiment based on the flowcharts 1 and 2. Thereby, the effect similar to the modification 1 of 1st Embodiment is acquired.

  In the first embodiment and the first modification, the multi-plate clutch mechanism C / T and the switching mechanism M are interposed on the axles Arr and Afr of the right front wheel and the right rear wheel. However, the present invention is not limited to this, and the multi-plate clutch mechanism C / T and the switching mechanism M may be interposed on the axles Arl and Afl of the left front wheel and the left rear wheel. Similarly, in the second embodiment and the first modification, the multi-plate clutch mechanism C / T or the switching mechanism M interposed on the right front wheel axle Afr may be interposed on the front left wheel axle Afl. .

  Further, the propeller shaft Sp may be connected and disconnected by interposing the multi-plate clutch mechanism C / T and the switching mechanism M interposed in the right front wheel axle Afr and the right rear wheel axle Arr in the propeller shaft Sp. As described above, the same effect can be obtained by controlling connection / disconnection of the propeller shaft Sp connected to the front wheel side differential D / Ff or the rear wheel side differential D / Fr according to the present invention.

  Further, in the switching control unit 28 of the drive state control device in the present embodiment, when disconnecting the multi-plate clutch mechanism C / T, the rotation speed of the rear left and right wheels (average rotation speed) and the rotation of the front left and right wheels The number (average rotational speed) was confirmed, and the differential rotational speed was calculated to control cutting. However, the present invention is not limited to this mode, and the output shaft rotation speed R1 (that is, the vehicle speed V) of the automatic transmission T / M and the steering angle θ of the steering are obtained. The number Rfr may be calculated, the connection of the switching mechanism M may be controlled by releasing the connection of the multi-plate clutch mechanism C / T according to the calculated timing of the differential rotation speed Rfr.

  In the first and second embodiments, the front left and right wheels and the rear left and right detected by the left and right wheel rotation speed sensors Vfr, Vfl, Vrr, and Vrl after the multi-plate clutch mechanism C / T is in the connected state. The multi-plate clutch mechanism C / T was disconnected (released) at a timing corresponding to the detected differential rotational speed Rfr with the wheel, and the switching mechanism M was controlled to be in a connected state. At this time, the timing according to the detected differential rotation speed Rfr is set to the timing at which the switching mechanism M can be connected immediately after the multi-plate clutch mechanism C / T is disconnected.

  However, the present invention is not limited to this mode, and control may be performed as shown in the graph of FIG. That is, for example, after the rotation of the propeller shaft Ap and the rear left and right wheels is connected, the connection of the multi-plate clutch mechanism C / T is disconnected (released) at a predetermined timing. After that, for a while, the propeller shaft Ap is rotated only by the inertial force to naturally reduce the rotational speed. Then, when the reduced number of rotations and the number of rotations of the front left and right wheels substantially coincide after a predetermined time has elapsed, connection control is performed by the switching mechanism M. The disconnection control of the multi-plate clutch mechanism C / T and the switching mechanism M may be performed at such timing.

  Further, in the flowchart 2 of the present embodiment, in step S28 to step S30, the switching control unit 28 determines that the front left and right wheel rotation speed (average rotation speed) equal to the propeller shaft rotation speed R2 and the rear left and right wheel rotation speeds. While confirming the rotational speed (average rotational speed), it was determined whether or not the differential rotational speed Rfr of the front and rear left and right wheels became a predetermined differential rotational speed Rm. If the predetermined rotational speed Rm is reached, in step S31, the multi-plate clutch mechanism C / T is disconnected and disconnected, and in step S32, the other clutch device (the first clutch device provided on the rear left and right wheels side) The switching mechanism M, which is a two-clutch device, was controlled to the connected state.

  However, the present invention is not limited to this aspect, and control may be performed by the following method. That is, in the processing unit corresponding to step S28 to step S30, the deceleration of each of the front left and right wheel rotation speeds and the rear left and right wheel rotation speeds is calculated from the left and right wheel rotation speeds acquired in the flowchart 1. Next, a time T from the deceleration to the time when the difference rotation speed Rfr between the front left and right wheel rotation speed and the rear left and right wheel rotation speed reaches a predetermined difference rotation speed Rm is predicted. When the time T is reached, in step S31, the multi-plate clutch mechanism C / T is disconnected, and in step S32, the other clutch device (second clutch device) is provided on the rear left and right wheels. The switching mechanism M is controlled to the connected state. Then, the connection control of the multi-plate clutch mechanism C / T may be performed thereafter. This also provides the same effect.

DESCRIPTION OF SYMBOLS 11,41 ... Output shaft, 12 ... Output shaft, 13 ... Output output shaft, 14 ... Hypoid gear, 16 ... Spline outside input shaft, 17 ... Spline outside output shaft, 18 ... Sleeve, 19 ... Spline inside sleeve, 22, 23 , 42, 43 ... friction member, 24, 44 ... case, 25 ... 2WD running determination unit, 26 ... steering angle determination unit, 27 ... deceleration determination unit, 28 ... switching determination unit, Aw ... steering angle sensor, C / T ... one clutch device (multi-plate clutch mechanism), D / Ff ... front wheel side differential, D / Fr ... rear wheel side differential, M ... the other clutch device (switching mechanism), Sp ... output output shaft (propeller shaft) Vfr, Vfl, Vrr, Vrl ... left and right wheel rotational speed sensor, Vp ... propeller shaft rotational speed sensor, Vt ... output Yafuto rotation speed sensor, θ ... steering angle.

Claims (4)

A first differential mechanism that is rotationally coupled to an output shaft of a transmission connected to a drive source and distributes rotational driving force to one of the left and right wheels of the front left and right wheels and the rear left and right wheels;
A first clutch device detachably connecting and disconnecting the output shaft of the transmission and the other of the front left and right wheels and the rear left and right wheels;
A second differential mechanism that is rotationally connected to the output output shaft of the first clutch device between the first clutch device and the other left and right wheels and distributes the rotational driving force to the other left and right wheels;
A second clutch device detachably connecting and disconnecting the output output shaft of the first clutch device and the other left and right wheels;
Left and right wheel rotation speed sensors for detecting the rotation speed of the front and rear left and right wheels;
An output shaft rotational speed sensor for detecting the rotational speed of the output shaft of the transmission;
A steering angle sensor for detecting the steering angle of the steering;
An output output shaft rotational speed sensor for detecting the rotational speed of the output output shaft of the first clutch device;
One of the first and second clutch devices is a multi-plate clutch that is frictionally engaged by the engagement of a friction member and can connect the input shaft and the output shaft of the clutch device,
The other clutch device is a dog clutch capable of connecting the input shaft and the output shaft by fitting a fitting portion when a differential rotational speed between the input shaft and the output shaft of the clutch device is equal to or lower than a predetermined rotational speed. ,
A two-wheel drive determination unit that determines that the rotational driving force is input to only one of the left and right wheels and is in a two-wheel drive driving state;
A steering angle determination unit that determines that the steering angle is operated by a predetermined amount or more;
A deceleration determination unit that determines that the vehicle is decelerating;
When switching to four-wheel drive, the multi-plate clutch is connected, and the detected differential rotation speed between the front left and right wheels and the rear left and right wheels detected by the left and right wheel rotation speed sensor, or the output shaft of the transmission The dog clutch is controlled to be in a connected state after releasing the connection of the multi-plate clutch at a timing according to the calculated differential rotation speed between the front left and right wheels and the rear left and right wheels calculated from the rotation speed of the vehicle and the steering angle. Then, a switching control unit for controlling the connection of the multi-plate clutch,
A vehicle drive state control device comprising: In claim 1,
A driving state control device for a vehicle, wherein a chamfer is formed at at least one tip of the fitting portion of the dog clutch. In claim 1 or claim 2,
The drive state control device for a vehicle, wherein the one left and right wheel is the front left and right wheel. A first differential mechanism that is rotationally coupled to an output shaft of a transmission connected to a drive source and distributes rotational driving force to one of the left and right wheels of the front left and right wheels and the rear left and right wheels; the output shaft of the transmission; A first clutch device that detachably connects the other of the front left and right wheels and the rear left and right wheels, and an output output shaft of the first clutch device that rotates between the first clutch device and the other left and right wheels A second differential mechanism coupled to distribute the rotational driving force to the other left and right wheels; and a second clutch device that detachably connects and disconnects the output output shaft of the first clutch device and the other left and right wheels. A left and right wheel rotational speed sensor for detecting the rotational speed of the front and rear left and right wheels, an output shaft rotational speed sensor for detecting the rotational speed of the output shaft of the transmission, and a steering angle of the steering A steering angle sensor for output, and an output output shaft rotational speed sensor for detecting the rotational speed of the output output shaft of the first clutch device, and one of the first and second clutch devices. Is a multi-plate clutch that can be frictionally engaged by the engagement of the friction member and connect the input shaft and the output shaft of the clutch device, and the other clutch device is the difference between the input shaft and the output shaft of the clutch device. A dog clutch capable of connecting the input shaft and the output shaft by fitting of a fitting portion when the rotational speed is equal to or lower than a predetermined rotational speed;
A two-wheel drive determination step for determining that the rotational driving force is input to only one of the left and right wheels;
A steering angle determination step of determining that the steering angle is operated by a predetermined amount or more;
A deceleration determination step for determining that the vehicle is decelerating;
When switching to four-wheel drive, the multi-plate clutch is connected, and the detected differential rotation speed between the front left and right wheels and the rear left and right wheels detected by the left and right wheel rotation speed sensor, or the output shaft of the transmission The dog clutch is controlled to be in a connected state after releasing the connection of the multi-plate clutch at a timing according to the calculated differential rotation speed between the front left and right wheels and the rear left and right wheels calculated from the rotation speed of the vehicle and the steering angle. Then, a switching control step for controlling the connection of the multi-plate clutch,
The driving state control method of the vehicle by the above.

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